Principle of pneumatic separation: The pneumatic separation defines the action of floating and separating certain material in an air flow. By setting a certain airflow velocity, it makes the lighter part of the materials, with the lower suspending speed than the set speed, move upwards, the heavier parts move otherwise downwards, so the materials are essentially separated into two parts of the lighter and the heavier. This principle is widely applied in various industries, such as CN201454852 U discloses a device for separating heavier high-qualified seeds.
CN 2922496 Y discloses a device for pneumatic separating invalid heavier stems and debris from cutting tobacco, in which the lighter and effective cutting tobacco is carried away, then is separated with the gas-materiel separation equipment after the pipeline transportation. CN 102626257 A and CN 2791087 Y disclose a device for use in separating mixed material such as tobacco slice and stem. The effective tobacco slice being separated is transported by air, is separated thereof then by use of the rotary discharge equipment. CN 101053868A discloses a device provided with binary silos for separating tobacco materials, wherein the different velocities are adopted in two silos result in twice separation of materials, the lighter and effective materials are carried away by air, then is separated with the gas-material separation equipment after the pipeline transmission.
It is indispensable for the lighter and effective materials to be sorted by using the devices mentioned above, the gas-material separation equipment after the pipeline transportation. The moisture of material should be reduced, the mechanical friction become more intense in the processes of transport and separation. As a result, it makes material size becoming smaller, and leads to production of large amounts of detritus, reducing use value for the material. Additionally, the devices above can simply implement the singular function of sorting, as for managing gas-material separation which is necessarily combined with other discharge equipment in addition, the correspondent equipment is complex and high energy consumption.